-LRB- CNN -RRB- -- As the global population hits 7 billion in the coming days , nations can take steps to tackle critical challenges and prepare for the arrival of billions more people this century , the United Nations said Wednesday .

The milestone is expected to be reached on October 31 .

`` With planning and the right investments in people now ... our world of 7 billion can have thriving , sustainable cities , productive labor forces that can fuel economic growth , youth populations that contribute to the well-being of economies and societies , and a generation of older people who are healthy and actively engaged in the social and economic affairs of their communities , '' UNFPA , the United Nations Population Fund , said in a new report .

Among the steps the report focuses on are empowering young people with economic opportunities ; planning for the growth of cities ; developing programs to share and sustain the Earth 's resources ; and improving education , including sexual education .

A U.N. report published in May predicts a global population of 9.3 billion by 2050 , and more than 10 billion by the end of this century .

`` With only a small variation in fertility , particularly in the more populous countries , the total could be higher : 10.6 billion people could be living on Earth by 2050 and more than 15 billion in 2100 , '' says the Population Division of the U.N. Department of Economic and Social Affairs .

Much of the increase will come in Africa and Asia .

In light of growing concerns about the global economy , the new UNFPA report highlights financial dangers facing people in industrialized and developing nations .

`` While labor shortages threaten to stymie the economies of some industrialized countries , unemployed would-be migrants in developing countries are finding more and more national borders closed to them and the expertise they may have to offer . And while progress is being made in reducing extreme poverty , gaps between rich and poor are widening almost everywhere . ''

The 7 billion mark is a huge spike from less than a century ago . In 1927 , the global population was 2 billion .

It was only 13 years ago that the population was at 6 billion , the United Nations says .

Changing demographics are quickly reshaping the world in numerous ways .

People under the age of 25 make up 43 % of the world 's population , the United Nations says .

About half of the world 's population lives in cities . Within about 35 years , two-thirds will , it says .

While reaching 7 billion in 2011 has long been predicted , the new U.N. report Wednesday -- `` State of World Population 2011 '' -- highlights changes and trends to offer a complex picture .

In a summary of the report , the agency notes that `` women are on average having fewer children than they were in the 1960s . ''

The number of children a woman is expected to have dropped from an average of 6 to 2.5 , the report says .

But there are far more women than there were in the 1960s .

`` In some of the poorest countries , high fertility rates hamper development and perpetuate poverty , while in some of the richest countries , low fertility rates and too few people entering the job market are raising concerns about prospects for sustained economic growth and the viability of social security systems , '' the summary says .

A few more facts and figures from the report :

-- Today there are 893 million people over the age of 60 ; by the middle of the century , that number will rise to 2.4 billion .

-- Asia will remain the most populous area this century , but Africa `` will gain ground as its population more than triples , increasing from 1 billion in 2011 to 3.6 billion in 2100 . ''

-- The combined population of other areas -- including the Americas , Europe , and Oceania -- is currently 1.7 billion , and is expected to rise to nearly 2 billion by 2060 , `` then decline very slowly . ''

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NEW : World population could surpass 15 billion by the end of the century , the U.N. says

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In 1927 , the world 's population was 2 billion

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People under age 25 make up 43 % of the current population

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Africa 's population is expected to more than triple this century